楼主基本上全责了:
19. The driver of automobile “A” is 100 per cent at fault and the driver of automobile “B” is not at fault for an incident that occurs,
(a) when automobile “A” is backing up;
(b) when automobile “A” is making a U-turn; or
(c) when the driver of, or a passenger in, automobile “A” opens the automobile door or leaves the door open. R.R.O. 1990, Reg. 668, s. 19.
交给自己的保险公司处理吧。